The present invention relates generally to steering column support structures, and more particularly to a steering column support structure including break-away bars that securely hold the steering column to the instrument panel without hindering the collapse of the steering column during an accident.
It is desirable to have a steering column of a vehicle that is securely attached to the frame of the automobile so as to ensure safe operation thereof for the life of the automobile. Generally, this is accomplished by bolting the steering column to the instrument panel which is further secured to the frame of the automobile. However, it is further desirous to allow for the steering column to disengage from the instrument panel upon the application of a force during an accident.
It is known in the art to attempt to solve these contradictory goals by using polymer capsules to support the mounting bracket (such as disclosed in commonly assigned U.S. Pat. No. 5,390,955 herein incorporated by reference) and the steering column that are designed in such a way as to break away under a given force. Thus, the steering column is allowed to break away from the instrument panel upon the application of a force in the event on an accident.
Further, the polymer capsules may fall out during installation and may change in shape which can cause the capsules to weaken or xe2x80x9ccreep.xe2x80x9d This creep can cause buzz/squeak/rattle (BSR) problems which are unwanted during the operation of the vehicle. Furthermore, the polymer capsules are relatively fragile and can become damaged prior to installation thus requiring the disposal of the part.
The present invention provides a break-away bar that will overcome the disadvantages of the prior art polymer capsules. It is an object of this invention to form these break-away bars from the same material as the remainder of the steering column mounting bracket. The magnesium or other metallic material of which the steering column mounting bracket is made is rigid and is not susceptible to being misshapen and is much more predictable than a polymeric material. Thus, the break-away bar will have a consistent break-away load, not be susceptible to BSR, and not break unintentionally during installation.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood however that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.